According to the American Chronic Pain Association, more than 50 million Americans suffer from some form of chronic pain. The most common types of pain include arthritis, lower back pain, bone/joint pain, muscle pain, and fibromyalgia. Therapeutic ultrasound is a noninvasive, drug-free treatment used for musculoskeletal and joint pain.
At the end of February, the FDA granted 510(k) clearance for SAM®, from ZetrOz, Inc., Trumbull, CT, the first long-duration, wearable ultrasonic diathermy device for applying deep therapeutic treatment.
The device uses high-frequency ultrasonic excitations to produce deep mechanical stimulation within the body, increasing circulation, reducing inflammation, and pushing nutrients through the body’s cellular structures, explains product inventor and company cofounder, George K. Lewis, Jr., PhD, who also serves as the Chair of Therapeutic Ultrasound for the American Institute of Ultrasound in Medicine. Here he explains the backstory, and current state of wearable ultrasound.
An Electrifying Beginning
I was raised on ultrasound technology. My father, Dr. George K. Lewis, Sr., a distinguished scientist and engineer in biomedical ultrasonics and array design, had long experimented with ultrasound technology and holds copatents with me on variations of the miniaturized device technology. Before I was in high school, I was working in my father’s R&D facility assisting him on acoustic measurements, transducer soldering, and becoming integrated into the ultrasound community.
Once I took interest in the therapeutic properties of ultrasound in graduate school, he helped me pursue my goal of miniaturizing ultrasound for self-administered pain relief. While pursuing a doctorate degree in Biomedical Engineering at Cornell University, I started integrating ultralow impedance ultrasound miniaturization technology into my academic and industry research and began exploring commercialization efforts to include the technology in noninvasive surgeries, pre-natal imaging, cancer ablation, and wound healing.
I attended Cornell as a presidential life science fellow, with a full scholarship to pursue a PhD in the biomedical engineering. In my first year, I became interested in brain cancer and other neurological diseases, and formed a thesis committee around developing a novel ultrasound-based drug delivery strategy that employed convective-drug infusions directly into the brain, coupled with ultrasound-controlled distribution of the neuronal therapy.
My PhD committee consisted of biomolecular and chemical engineering, neurobiology, and mechanical engineering professors that were supportive of my idea—however, I had to develop the equipment and experimental techniques to design, test, and evaluate my proposed ultrasound-based drug delivery device. I was fortunate to have also received research support from the National Science Foundation and National Institutes of Health, which allowed me to begin to design the first “ultrasonic drug delivery needle” and the associated driver and control electronics of the system.
While I was in the process of building the system and following engineering design notes available in the literature, I was accidently electrocuted with more than 1,000 volts from a high-power ultrasound driver circuit that I designed. After getting thrown back to the floor, feeling dizzy and nauseous, and being run through a whole suite of cardiac tests by the EMTs—I had my epiphany. To design a low-voltage, ultralow-impedance ultrasound system that is safe yet powerful…and with that, the technology was invented.
The first commercial product, a wearable ultrasound device for pain, was prototyped in 2008 and launched for commercial distribution into the medical market in 2014 with the help of my father. The battery-operated ultrasound device was later refined into various configurations for a number of biomedical applications— this included the wearable therapeutic ultrasound device.
ZetrOZ was awarded a few prestigious grants to bring this technology to fruition. These include a recent NIH Grant for $397,000, a Connecticut Innovations investment of $1.3 million, $100,000 award for primary healthcare innovation, and $50,000 as a runner-up in the 2011 Creative Core Emerging Business Competition. Along the way, we have also received a number of awards for the technology, including Most Impactful Technology awards, the Empact 100 Award and Most Innovative Research awards.
How It Works
Ultrasound is a mechanical wave that enhances the body’s natural process of providing circulation to tendons, ligaments, muscles, etc. Biological tissues are poroelastic and are similar to a sponge. The transport of fluids is increased when mechanically stimulated with compression and rarefaction forces. Ultrasound, non-invasively, acts on tissues in these ways by squeezing and opening up tissue, moving nutrient molecules to improve the cellular environment, and increasing total transport kinetics in tissue via mild, painless warmth. Its effects are subtle, taking time via daily “slow release” which makes the technology so effective.
Going deeper into the technology, ultrasound works via the mechano-transduction of cellular pathways, elastically perturbing the tissue and changing the permeability of tissues, nerves, cartilage, ligaments, tendons and muscle. The patient feels a soothing, thermal and numbing sensation as a flood of nutrients is transported in and the “waste” is removed. Vasodilatation due to local nitric oxide release and thermal regulatory effects of tissue broadens the utility of ultrasound. The therapeutic modality can also create a biological cascade causing angiogenesis—the stimulation of new blood vessel growth.